CUCM uses the best match routing method, there is no order of what can/should be used first.

The CSS defines what you can reach, and the order of the partitions only matters under 1 circumstance: equally good matches exist in 2 or more partitions. Only then, the 1st one from top to bottom will be used.

If that condition is not met, the partition order doesn't matter. The best match is used to route the call.

I'd suggest you to read the whole dial plan chapter from the SRND.

ALL calls match an inbound and outbound dial-peer, whether it's the default one or one you configured.

This for H323 since you're mentioning dial-peers.

HTH

java

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Its never fun trying to ad-hoc explaination of css or pt.

Here are a few links:

http://itknowledgeexchange.techtarget.com/cisco-voice/tag/calling-search-spaces/

The ol' lock and key explanation.

And the SRND guide Java mentioned:

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/7x/dialplan.html

Thanks for the great explanation and information.

I am new to voice and I am trying to sort out the relationships between everything.

Right now, in my mind I don't see how the components are associated to make the call flow work.

Hi Wilson,

You are doing great so far it seems and don't worry, this stuff is

hard to understand

You are lucky to have received answers from two awesome NetPro's

and two of my faves, Tommer and Java! I'll try to add another approach;

Here are some excerpts from a Cisco doc that really explains Partitions and CSS perfectly;

Understanding Partitions and Calling Search Spaces

A partition comprises a logical grouping of directory numbers (DNs) and route patterns with similar reachability characteristics. Devices that are typically placed in partitions include DNs and route patterns. These entities associate with DNs that users dial. For simplicity, partition names usually reflect their characteristics, such as "NYLongDistancePT," "NY911PT," and so on.

A calling search space comprises an ordered list of partitions that users can look at before users are allowed to place a call. Calling search spaces determine the partitions that calling devices, including IP phones, soft phones, and gateways, can search when attempting to complete a call.

Examples

Calling search spaces determine partitions that calling devices search when they are attempting to complete a call.

For example, assume a calling search space named "Executive" includes four partitions: NYLongDistance, NYInternational, NYLocalCall, and NY911. Assume that another calling search space named "Guest" includes two partitions, NY911 and NYLocalCall.

If the Cisco IP Phone that is associated with a phone or line is in the "Executive" calling search space, the search looks at partitions "NYLongDistance," "NYInternationalCall," "NYLocalCall," and "NY911" when it attempts to initiate the call. Users who are calling from this number can place international calls, long-distance calls, local calls, and calls to 911.

If the Cisco IP Phone that is associated with a phone or line is in the "Guest" calling search space, the search looks only at the "NYLocalCall" and "NY911" partitions when it initiates the call. If a user who is calling from this number tries to dial an international number, a match does not occur, and the call cannot be routed.

Cheers!

Rob

As always, thanks Rob.

You guys are great and have given me some good information.

I appreciate it.

tcatlinins wrote:
Wow, lots of stuff here... so lets try and tackle few here.
You can turn on dependecies within CUCM to where everything is "touching" other configuration parameters.
When you pull up a say a device pool, in the upper right corner, drop down the menu and select (Related Links) Dependecy Records.
It will then pull  a list with everything that it is "touching".    You will have to turn it on in the Enterprise Serivce Paramenters.  It will also prompt you how to do this if its not on.
It really does not matter by what type of call routing you are doing.  It matters on the calling search space and partition.
For example:
If I have x4000 in Parition "Line1_PT"   
Calling Search Space  "local_CSS"
So you would see local_CSS with Line1_PT as a member of this css.
If I have a router pattern that is  9.XXXXXXX and its CSS is Local_CSS,     x4000 picks up the phone and dials 9.XXXXXXX  it will pick the Route Pattern 9XXXXXXX.
Now, if I have another scenario where I have to translate an outbound number for some reason, I can create another partition say "911_PT" and another Calling search space called "911_CSS"
Then order the the PTs with each CSS for priority purposes.
There is no real order of which Call Routing feature it will use first.  Its based on calling space and partition.
If you are using H323 to send 9xxxxxxx out to the router, the router will need to have h323 and dial peers setup to send the call out to the PSTN.
If its MGCP, the call is "packaged" and send to the router using MGCP.
The device pool has nothing to do with the line unless you are using Local Route Groups.  (another concept).   The Device Pool simply manages the devices in that pool for settings such as SRST, MRGs CUCM groups etc.

Thanks,

1. The dependancies suggestion is appreciated, I see that now.

2. So if I have calling search space "local_CSS", the phone would be in the CSS and I could have a different partition for each line, line 1 in "line1_PT" and line 2 in "line2_PT". or both lines in the same partition. Is this correct?

(trying to establish the relationship of the phone, lines to CSS, partitions)

3. When you say "it really does not matter what kind of call routing you are doing", what types of call routing are you talking about?

4. "order the PTs with each CSS for priority reasons" Can you explain?

5. Dial peers are for h323 only, MGCP does not use them?

Calling Search Space : "Who can call YOU"

Partition: "Who YOU can call"

MK

I'd suggest you to read all the material that has been already provided to get a better understanding as everything we're explaining comes from there.

If you don't read the material you won't get the concepts and explanations, and if you read it, you will get the answers by yourself.

2. So if I have calling search space "local_CSS", the phone would be in the CSS and I could have a different partition for each line, line 1 in "line1_PT" and line 2 in "line2_PT". or both lines in the same partition. Is this correct?

A DN has a partition.

DNs have CSS

Some devices can have CSS

You really get this knonwledge by working everyday with CUCM there is no table of "this has CSS, this has partition"

The relationship of CSS and partitions is in the SRND dial plan chapter, read it.

3. When you say "it really does not matter what kind of call routing you are doing", what types of call routing are you talking about?

CUCM ONLY uses best match routing for digit analysis. Read previous post, also explained in SRND.

4. "order the PTs with each CSS for priority reasons" Can you explain?

Does not matter except for 1 circumstance, read my previous post. Also explained in SRND.

5. Dial peers are for h323 only, MGCP does not use them?

Not for routing decisions, just to let MGCP control the endpoint.

3 out of 4 questions are in the SRND

HTH

java

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